Apparatus for driving points, of the kind used by framers and glaziers, is well known in the art. A particularly desirable form of point driver is described and claimed in Kozyrski et al U.S. Pat. No. 4,699,307, issued Oct. 13, 1987.
It has in the past been recognized to be advantageous to power, by electrical or pneumatic means, machines of a nature broadly similar to point drivers. For example, Young U.S. Pat. No. 2,886,815, issued May 19, 1959, provides a clip application gun that includes pneumatic driving means for the staples utilized; and Maestri U.S. Pat. No. 3,720,364, issued Mar. 13, 1973, provides a tool for driving and setting headless nails and tacks, which may be operated mechanically or pneumatically.
In any such machine so powered, it is of course important that the action imparted by the pneumatic system be rapid and reliable. As far as is known, there has not heretofore been provided a pneumatically powered driver for framers' and glaziers' points which is entirely satisfactory from these, and other, standpoints.
Accordingly, it is the broad object of the present invention to provide a novel driver for framers' and glaziers' points, which is pneumatically powered and which affords highly reliable, rapid action for repetitively ejecting and driving such points.
A more specific object of the invention is to provide such a driver having incorporated therein a novel valve mechanism which is fundamental to the achievement of optimal operation.
Another object is to provide a novel valve mechanism that is suitable for use in a pneumatically powered point driver, for imparting thereto a highly reliable and rapid drive capability.
Additional objects of the invention are to provide such a point driver and valve mechanism affording the foregoing features and advantages, which are in addition relatively uncomplicated and inexpensive to manufacture, and highly efficient and convenient in use.